The following DATA INPUT are requested by the program:

Soon after will appear to the monitor the following result:

ULLAGE = 20.13 m.

From calibration table we can see that ULLAGE 20.13 m. is between gli ULLAGES 20.10 and 20.20 (metres),corresponding to the volumes 2835 and 2743 (Cubic metres). Computer will ask you the difference of said ullages (20.20 - 20.10 = 0.10 metres) and also the difference of the two volumes (2835 - 2743 = 92 cub.m.) as follows:

with the following result:

ULLAGE = 19.91 m.

You have to repeat the above procedure:
ULLAGE 19.91 metres is between ullages 19.90 and 20.00 with the following volumes 3017 and 2926; Computer will ask you the difference(20.00 - 19.90 = 0.10) and (3017 - 2926 = 91) as follows:

Ullage difference	0.10 metres
Volume difference	91 cub.m

The final calculation resulted to be :ULLAGE = 19.91 m.

When the last two results have the same values, the program will stop automatically and the observed ullage of 20.12 metres with the vessel aft. trimmed and listed, become 19.91 metres with the vessel Even Keel and ZERO listed. From calibration tables you can find the corrected volume at corresponding ullage of 19.91 metres.